Between Muchea and Woomera, I was trying to see the ground flares, a check for visibility. Deke gave me the attitudes to view the first flare, which involved a whopping, plus-80 degrees yaw maneuver and a pitch attitude of minus 80 degrees. But the cloud cover was too dense. “No joy on your flares,” I told Woomera and then went to drifting flight, where I found that just by rocking my arms back and forth, like attempting a full twist on the trampoline, I could get the capsule to respond in all three axes, pitch, roll, and yaw.
The Cape advised me to keep the suit setting where it was, because the temperature was coming down. I continued in drifting flight, and at capsule elapsed 01 02 41.5, over Canton, we checked attitude readings with telemetry. The Canton Capcom told me my body temperature was registering 102 degrees Fahrenheit, clearly a false reading.
Carpenter reported: “No, I don’t believe that’s correct. My visor was open; it is now closed. I can’t imagine I’m that hot. I’m quite comfortable, but sweating some.”
A food experiment had left crumbs floating in the cabin. I remarked on them, and reported the dutiful downing of “four swallows” of water. At his prompting, however, I could not confirm that the flight plan was on schedule. But I reported what I could: “At sunset I was unable to see a separate haze layer – the same height above the horizon that John reported. I’ll watch closely at sunrise and see if I can pick it up.”
Canton Capcom wished me “good luck,” and then LOS – loss of signal.
Everyone on the ground had had an eye on the fuel levels since the end of the first orbit. Gordo Cooper, capcom at Guaymas, had told me to conserve fuel, which was then at 69 percent capacity for the manual supplies, and 69 percent for the automatic. By the time I returned for my second pass over Kano, they had dropped to 51 and 69, respectively.
Carpenter reported: “The only thing to report is that fuel levels are lower than expected. My control mode now is ASCS.”
I explained to the Kano Capcom: “I expended my extra fuel in trying to orient after the night side. I think this is due to conflicting requirements of the flight plan.”
Live and learn. I spoke to the flight recorder, although Kano Capcom still had voice contact.
I should have taken time to orient and then work with other items. I think that by remaining in automatic I can keep – stop this excessive fuel consumption.
When I went to fly-by-wire aboard Aurora 7, very slight movements of the control stick in any axis activated one-pound thrusters and changed the attitude very slowly. Larger stick movements would activate the twenty-four-pound thrusters, which would change the attitude much more quickly but use twenty-four times as much fuel. If the manual proportional control mode were chosen, the change capsule attitude would be proportional to stick movement, just as an airplane. (Move the stick a little, get a little bit of thrust; move it halfway, get half thrust; move it all the way, get full thrust.) Each increment of movement had attendant increases in fuel expenditure. If, however, both control modes were chosen concurrently – and this happened twice during MA-7 as a result of pilot error – then control authority is excessive and fuel expenditure exorbitant.
For my flight the twenty-four-pound thrusters came on with just a wrist flick, that I then corrected with a wrist flick in the other direction. This countermovement often activated the twenty-four-pound thrusters yet again, all for maneuvering power not required during orbital flight. The high thrusters weren’t needed, really, until retrofire, when the powerful retrorockets might jockey the capsule out of alignment. The design problem with the three-axis control stick as of May 1962 meant the pilot had no way of disabling, or locking out, these high-power thrusters. Because of my difficulties and consequent postflight recommendations, follow-on-Mercury flights had an on-off switch that would do just that, allowing Wally Schirra and Gordo Cooper to disable the twenty-four-pound thrusters. Gemini astronauts had a totally different reaction control system.
But I understood the problem and resolved to limit my use of fuel. Consulting my index cards, I saw that I still had voice reports to make on several experiments – the behavior of the balloon, still tethered to the spacecraft; a night-adaption experiment; and the ingestion of some more solid food. Holding the bag, however, I could feel the crumbled food. If I opened it, food bits would be floating through my work space. I made a mental note: “Future flights will have transparent food bags.” See-through bags would make crumb strategy easier during these zero-G food deployments. I was beginning to regret my lack of training time.
Before loss of signal, Kano Capcom asked me to repeat my fuel-consumption critique.
Capcom asked: “Would you repeat in a few words why you thought the fuel usage was great? Over.”