‘Hardest part is over’

The news vans, cameras and reporters are slowly moving out of the Jet Propulsion Laboratory parking lot after a weekend of crossed fingers, lucky peanuts and amazing scientific and engineering achievement.

Just before 5 p.m on Sunday the Phoenix spacecraft used its descent thrusters and landed on its three legs on the Martian surface, all according to plan. The landing procedure was last attempted in 1999 with the Mars Polar Lander but communication was lost with the spacecraft shortly before it entered Mars’ atmosphere. This landing was “perfect,” according to Barry Goldstein, Phoenix project manager.

Since its landing, the spacecraft has been operating according to plan with only one glitch; the relay of information from the Mars Reconnaissance Orbiter (MRO). The orbiter is one of two that was planned to communicate with Phoenix during morning and evening flyovers. Although it had been tested over 100 times before the landing, the orbiter’s UHF radio antenna stopped working. The MRO team is working to find the reason for the problem. In the meantime the second orbiter, the Odyssey, will be doing double duty as it relays the Phoenix information to and from Earth.

“[MRO] was working. We have done a lot of testing with the rovers, plus all the testing on Earth,” said Mark Garcia, deputy mission manager at JPL.

Garcia said that the only way to get instruction to and data from Phoenix to Earth is via the orbiters.

The communication problem delayed the deployment of more testing, including moving the spacecraft’s digging arm in to place. The arm is expected to be released from its prelaunch position sometime today, the procedure will be completed on Friday.

Despite the communication problem, Garcia said everyone at JPL is very happy with the spacecraft’s performance, although he admits there were some tense moments as the team waited for the landing. On Sunday night all at JPL listened closely to Richard Kornfeld, deputy systems engineer on the entry descent and landing team, and the voice of mission control for the landing.

“All personnel are to be at their station,” said Kornfeld.

That call went out to the mission team shortly after 4:30 p.m. on Sunday. JPL’s vn Karman auditorium was full of international and national press. The Phoenix team were in mission control. Reminiscent of the Apollo landings on the moon decades earlier, Kornfeld’s voice was heard as he announced the landing sequence.

“Waiting for separation…. Confirm separation,” he announced.

Cheering was heard from mission control and the pressroom, then silence. Kornfeld continued to announce the sequence, step by step as reporters typed frantically on their laptops.

“Five, four, three, two, one,” Kornfeld counted down as the spacecraft entered the Martian atmosphere. “As the atmosphere gets hotter we may see some blackouts occur,” he warned.

But those blackouts didn’t occur and another small, tempered cheer from mission control. The traditional lucky peanuts were being handed out to all in the control room and fingers were crossed.

“We have data lock-up,” he said followed by another cheer with deep breaths and hugs. They knew they were close to the landing. The team continued to congratulate each other, then Dr. Fuk Li, manager of Mars Exploration Program at JPL, held his finger to his lips to quiet everyone. This worked; even in the pressroom all held their breath.

“Five hundred meters, 400, 250, 150, 100, 80, 15 meters standing by for touchdown,” Kornfeld said. “Touchdown detected. The Phoenix has landed! The Phoenix has landed!”

Cheer erupted in mission control.

“Unbelievable,” said Goldstein. “The hardest part is over but there is still a lot of drama to unfold.”