July-August 1982:space activities report

EXTENDED VIKING "SUCCESSFUL"

The extended mission of Vikings 1 and 2 has been declared to be a complete success. Four Viking spacecraft, two orbiters and two landers, arrived at the Red Planet in the summer of 1976, and the Viking 1 lander is still returning data. All four spacecraft returned valuable information on the meteorology and geology of Mars far longer than called for in original mission plans.

The extended mission began after the spacecraft completed their highly successful initial mission. The two landers completed a complex set of biochemical experiments aimed at determining if there was life on the planet. The results of these experiments, which included retrieving surface samples with robot arms and analysing them in microbiological laboratories, were tantalising but inconclusive. All four spacecraft provided spectacular photographs of the planet, and instruments returned a wealth of data on the atmosphere and climate of Mars. The extended mission gathered long-term data on meteorology to assist in a study of Mars’ seasons, ana returned high resolution photographs to continue geotogicarand geochemical studies.

The long-lived Lander 1 now enters a third phase of explo¬ ration, a continuous but low activity programme to return imaging, meteorology, radio science and engineering data on eight-day cycles from now until 1987.

DOUBLE LANDING ON VENUS

Russia’s latest two Venus probes, Veneras 13 and 14,made successful soft-landings on the planet on March 1 and 5 respectively, writes Andrew Thomson. The probes sent back the first colour photos of the surface and performed the first onboard soil-sampling experiments.

Russia’s Venus programme began with a string of failures before the first soft-landing in 1970. Veneras 9 and 10 - larger, redesigned craft - radioed back the first surface photographs in 1975. Veneras 11 and 12 in 1978 soft-landed successfully, but it seems that their instruments did not function as planned - no pictures were ever released, and the whole mission was overshadowed by the highly-successful US Pioneer-Venus mission.

Venera 13 landed at 7.5° South, 303° longitude, recording temperatures of 457° C and pressure of 89 atmospheres. It operated for 177 minutes (four times the designed lifetime), returning eight panoramic photographs. Venera 14 landed at 13.25° South, 310° longitude, recording temperatures of 465° C and pressure of 94 atmospheres. It operated for 57 minutes,returning pictures which included the first colour view of the orange Venusian sky. Both craft used parachutes down to a height of 47 km, and large saucer-like rims around the top of the craft for aerodynamic braking for the remainder of the descent.

Previous Soviet probes had landed “blind” because no one knew what lay below the opaque clouds. However, for Veneras

13 and 14 the US shared Pioneer-Venus radar data with the Soviets (the first-direct cooperation in planetary exploration), and the landing sites were chosen with this in mind. Venera 14 was aimed to land on a low-lying basin area and Venera 13 on rolling plains to the north-west; both sites were east of the Phoebe Regio mountainous region. The objective was to investigate two of Venus’ four broad geological zones; Venera 14's basin area being lava plains, depressed regions flooded by lava flows from within the planet, Venera 13’s rolling plains being possibly part of Venus’ original crust (the other two zones are the Phoebe and Beta Regio mountainous volcanic regions, where Venera 9 and 10 landed, and the larger Ishtar and Aphrodite high plateaux regions, somewhat akin to Earth’s continents).

SPACE TELESCOPE

Bradford Smith, of the newly founded Space Telescope Institute, said just before the launch of STS-3 “We are hoping that it (the Space Telescope) will go up in early 1985, if it is on schedule.” He went on to describe his expectations for the data produced by the Space Telescope, writes Gerald Borrowman. “Well, for an example, we can look out and see part of our own Solar System to the planets that have not yet been visited by spacecraft, like Uranus, Neptune and Pluto. In fact, the Uranus observations will be important for Voyager as we are going to arrive at Uranus with that spacecraft in early 1986.”

VENUS/HALLEY 1984

An ESA conference of scientists and engineers involved in studying the return of Halley’s Comet to the inner Solar System in 1986 has provided details of the two Soviet Venera-Halley probes.

The Soviet mission to the comet is a combined Venus swingby/Halley fly-by mission. Two identical spacecraft will be launched during the period of 22-28 December 1984 and after carrying Venus entry probes to the vicinity of Venus (with the arrival and deployment of the probes between 14-22 June 1985), the two spacecraft will be re-targeted using Venus’ gravitational field to intercept Halley’s Comet in March 1986. The first spacecraft will encounter the comet on 8 March 1986, and the second about a week later. Fly-by velocity will be about 77 kms/second, at distances of around 10,000 km for the first spacecraft and 3,000 km for the second.

The Venera-Halley spacecraft is described as being three- axis stabilised. Its main features are large solar panels, a high-gain antenna dish, and an automatic pointing platform carrying those experiments that require pointing at the comet nucleus. This platform carries the narrow and the wide-angle camera, a three-channel spectrometer and the infrared sounder. All other experiments are body mounted, with the exception of two magnetometer sensors and various plasma probes and plasma wave analysers which are mounted on a 5 m boom. The total scientific payload will weigh 125 kg.

Comet-encounter data will be taken from 2 hours before closest approach until half an hour after, with several periods of data take before and thereafter, each lasting about two hours. The spacecraft is shielded from high dust impacts by a shield consisting of a 100 micron multilayer sheet 20-30 cm from the spacecraft, and a 1 mm aluminium sheet 5-10 cm from the spacecraft.

Details were also given at the gpnference of Japan’s Planet-A probe to Halley. This will be Japan’s first interplanetary mission, with launch from the Kagoshima Space Centre on 14 August 1985 by a three-stage Mu-3U rocket. To inject Planet-A on an encounter trajectory a fourth-stage kick motor with about 400 kg of propellant will be added. Direct injection without a parking orbit is to be employed. Since the injection error will be unknown until after launch, and the orbit-control capabilities of the on-board attitude and velocity control system are limited, Planet A cannot be precisely aimed at the comet nucleus. It is estimated that fly-by distance will be between 10,000 and 100,000 km. A test spacecraft, tentatively designated MS-T5, will be launched six months before Planet-A to prove the capability of the launch vehicle.

THE LAUNCH OF STS-3

The public and press are kept informed of what is going on during a Shuttle launch by NASA’s public affairs department. Here is an edited transcript of the announcements made at the launch site as Columbia climbed into space for the third time:

T-5 minutes 30 seconds and counting. The development flight instrumentation recorders are on. The DFI provides measurements of temperatures, pressures and physical stresses on the Orbiter and the recorders store this information for playback after landing. T-5 minutes 12 seconds and counting. The Orbiter flight recorders are on.

The Auxiliary Power Units start up:

The APU’s provide hydraulic power to move the aerosurfaces and main engines for steering. T-4 minutes 42 seconds and counting. The firing circuits for the Solid Rocket Boosters’ ignition and range safety destruct devices have been armed. This is done with a motor-driven switch called a safe and arm device. T-4 minutes 20 seconds and counting. The main fuel valve heaters have been turned off in preparation for engine start. The main engines of the Orbiter will actually be started at T-6.8 seconds and it takes 3 seconds for them to reach 90 per cent thrust, at which time the solid motor ignition starts culminating with ignition and liftoff at T-0. T-3 minutes 55 seconds and counting. The final helium purge of the Orbiter's main engine has started to ensure that there’s no surplus hydrogen or oxygen in the area at the time of ignition. T-3 minutes 40 seconds and counting. The elevon, speedbrake, and rudder are being moved through a preprogrammed pattern to ensure that they are ready to be used during the flight.

T-3 minutes 28 seconds and counting. The Shuttle is now on internal power. However, the fuel cells are still receiving their fuels from the ground support equipment for about another minute. T-3 minutes 12 seconds and counting. The profile checks of the aerosurfaces are now complete and the engine gimbal or movement check of the main engines on the Orbiter is underway to ensure that they are ready for flight control. T-3 minutes and counting. T-2 minutes 55 seconds. The liquid oxygen valve for filling the External Tank is closed and pressurization has begun. After the tank is pressurized, the hold capability is limited to 3 minutes and 36 seconds. T-2 minutes 40 seconds and counting. The gaseous oxygen vent arm is being retracted.

T-2 minutes 30 seconds and counting. The fuel cells’ ground supply of oxygen and hydrogen has been terminated and the vehicle is now using its onboard supply. T-2 minutes 15 seconds. The main engines have been moved to start position. The astronauts have cleared the caution and warning memories in their onboard computers and verified there are no unexpected errors. T-2 minutes and counting. The astronauts are configuring the APU’s, the auxiliary power units, for a liftoff. The liquid hydrogen dump valve has been closed and pres¬ surization underway. T-1 minute 45 seconds and counting. The computers are automatically verifying the readiness of the main engines at the T-1 minute point.

T-1 minute 30 seconds and counting. T-1 minute 20 seconds and counting. T-1 minute 15 seconds. The liquid hydrogen tank is at flight pressure. Coming up on the one minute point in our countdown. One minute prior to the liftoff of the third Space Shuttle mission. T-1 minute and counting. The firing system for the sound suppression water system on the pad is armed. T-50 seconds and counting. T-45. We are 14 seconds .away from switching command of the countdown from the ground computers to onboard computers. The development flight instrumentation recorders are on. T-33 seconds and counting. The GOX [gaseous oxygen] vent arm is fully retracted and we’re switching controller to countdown to the onboard computers. T-25 seconds. The sequencer on the Orbiter is now controlling the final seconds. T-20 seconds. T-15, 14, 13, 12, 10, we are go for main engine ignition, 8, 7, 6, we have main engine ignition.

The Shuttle lifts off and the tower is cleared. One of the astronauts comments on the blue sky. Manoeuvres begin:

26 seconds. Roll manoeuvre completed. 30 seconds. 1 nautical mile in altitude, throttling engines down now to 68 per cent as programmed. 38 seconds. Plot board status looks good Mission Control. 42 seconds. Columbia now 3 nautical miles in altitude. 46 seconds. Coming up now on maximum aerodynamic pressure on the vehicle. 55 seconds past through max still looking good. Throttling engines back to a 100 per cent giving a go at throttle up. Mark 1 minute 10 seconds, Columbia now 7 nautical miles in altitude, 4 nautical miles down range, velocity now reading 2700 feet per second. Mark 1 minute 25 seconds. Columbia now 11 nautical miles in altitude 8 nautical miles down range.

The Commander warns of a cooling caution light, and SRB separation nears:

That was Jack Lousma reporting a freon loop light. 1 minute 40 seconds. Coming up on negative seats for altitude is too high for ejection seat use. Mark 1 minute 55 seconds. Columbia now 21 nautical miles in altitude 19 nautical miles down range. 2 minutes 2 seconds standing by for Solid Rocket Booster separation confirmation. 2 minute 15 seconds,confirm Solid Rock Boosters separation.

2 minutes 23 seconds onboard guidance is converging as programmed. Columbia is now steering for a precise window in space for main engine cutoff. 2 minutes 30 seconds standing by for 2 engine TAL capability. 2 minutes 45 seconds. CAPCOM Terry Hart says that Columbia now has a two engine auto landing capability. At Rota Naval Air Station, Spain. Columbia now 42 nautical miles in altitude, 58 nautical miles downrange. 3 minutes 30 seconds, Columbia now 51 nautical miles in altitude. Return status check in Mission Control by flight director Tom Holloway. 3 minutes 40 seconds. Lousma, Fullerton given a go to continue. Mark 3 minutes 45 seconds. Columbia now 53 nautical miles in altitude 104 nautical miles downrange. Really moving out now, the velocity reading now 7800 feet per second.

The astronauts are told they are "negative return”:

Four minutes 12 seconds; with that call up Lousma and Fullerton committed to space travel; they can no longer turn around and return to the launch site. F.our minutes 20 seconds.

The first indication of APU trouble comes in:

Four minutes 28 seconds, that was a report of an APU temp light, four minutes 33 seconds Columbia now 60 nautical miles. Five minutes 22 seconds. The PRESS to MECO call from CAPCOM Hart. Should Columbia loose about one engine, press on keep flying forward, Columbia's engines have enough energy to achieve normal altitude and velocity at cut off. Five minutes 35 seconds. Columbia now 63 nautical miles in altitude, 255 nautical miles downrange. Velocity now reading 12,300 feet per second.

APU 3 continues to give problems, and the Orbiter can land in Spain even if two main engines failed:

Six minutes 5 seconds, that report from CAPCOM Hart indicates if a two engine failure occurred, Lousma and Fullerton are capable of an emergency landing at ROTA Naval Air Station, Spain. That was Commander Jack Lousma reporting another message on APU 3. Six minutes 45 seconds, Columbia now 62 nautical miles in altitude, 398 nautical miles downrange. Mark, seven minutes, Columbia pitching over now, diving to decrease or increase their velocity, decrease altitude giving Columbia more favourable altitude. Seven minutes 10 seconds, standing by now for single engine PRESS to MECO call up by CAPCOM Terry Hart. Seven minutes 25 seconds, Columbia now 69 nautical miles in altitude, 545 nautical miles downrange.

The crew are advised to close down APU 3:

That was CAPCOM Terry Hart telling the crew to shut down APU 3. The single engine PRESS to MECO call says that the crew can achieve normal engine cut off targets even if two engines go out. Eight minutes four seconds, Columbia now 59 nautical miles in altitude, 630 nautical miles downrange. G forces building for Lousma and Fullerton, coming up to 3 Gs. Eight minutes 18 seconds, Columbia three main engines slowly being throttled back now, should be throttled at 68 percent at six seconds before main engine cutoff. Mark eight minutes 30 seconds,standing by now for main engine cutoff.

The main engines cut off and the External Tank separates:

Eight minutes 46 seconds, confirmed shutdown, Columbia again returned to space, not yet returned to orbit, standing by now for External Tank sep. Confirmed External Tank separation. Nine minutes two seconds, Columbia now performing an evasive manoeuvre moving below and beyond the External Tank. Nine minutes 14   seconds; go, no-go status check on Mission Control by Flight Director Tom Holloway for the first OMS burn [to achieve initial orbit]. 9 minutes 38 seconds, given a go for OMS-1 and the APU shutdown on time. 9 minutes 50 seconds. Columbia now manoeuvring to OMS-1 burn attitude using the two 6,000 pound thrust engines. OMS-1 will be positive grade moving Columbia forward and higher on her flight path, placing Columbia into a limited life time orbit. Report Columbia now at burn attitude. In burn attitude. 10 minutes 43 seconds the prop systems controller reports ignition two good engines. Columbia doing the first OMS burn now.

This is Shuttle Control, Houston. 12 minutes Mission Elapsed Time. Prop reports cut off on the first OMS burn. We have loss of signal now with Columbia through Bermuda. The next station to acquire will be Madrid'. 12 minutes 25 seconds. We expect Madrid acquisition at about 6 and a half minutes. This is Shuttle Control Houston. 15 minutes 24 seconds Mission Elapsed Time. Flight Dynamics Officer Ron Epps reports the following results for the first OMS burn. Time of ignition 10 minutes 33 seconds Mission Elapsed Time. Delta V 153 feet per second. Burn duration 1 minute 27 seconds. Resulting apogee of 130 nautical miles. Resulting perigee 46 nautical miles. At 15 minutes 58 seconds Mission Elapsed Time this is Shuttle Control Houston.