“Yes. The computer will takeover at balance mass jett immediately following de-spin.”
#
“Message from Newport,” said Jeff. “Go for EDL.”
“What else could they say?” said Abby.
“I dunno. Fasten your seatbelts and hang on?”
“Funny,” said Susan, nervously.
“They also say JPL is passing out the peanuts.”
“Why?” said Abby. “We’re a manned mission.”
“Just wishing us luck,” said Gabe.
“Guess we should have brought some peanuts.” said Jeff.
“I suppose. Entry Interface in 12 minutes. Two minutes to approach stage SEP. Abby, we’re a little high and hot. Before we cut it loose, I want you to burn retrograde at 50% for four seconds. Alignment is good. Whenever you’re ready.”
“Rog. Burning in 3, 2, 1, ignition. And… shutdown.”
“Beautiful. Jeff, the approach stage is all yours.”
“Roger. ASS in 90 seconds.”
Abby chuckled. “Best acronym we came up with.”
Jeff laughed. “Yeah. Gabe, if we just burn the AS RCS till it runs out of fuel, where will it come down?”
“I don’t know. If I had to guess, about 500 miles east-southeast of the station, somewhere south of Beer.”
“But it would come down, wouldn’t it? I mean, it’s not gonna make another orbit?”
“Oh, it’ll come down alright. Its periapsis will still be well into the atmosphere.”
“Okay, then why don’t we just do that? Give us plenty of separation.”
“Fine with me.”
“Roger that. Abby?”
“Okay. Ignition at EI minus ten plus one?”
“Make it ten plus two,” said Gabe. “We don’t want sep until we’re sure it’s burning.”
“Got it.”
“SEP in 55 seconds,” said Jeff.
“Rog. And we’ll de-spin immediately following ASS?”
“Yes,” said Gabe. “Please.”
“Whiner. And we’ll follow that with external balance mass jett?”
“Yes. We’ll need to be ready for a state update at EI minus 9 minutes, which I’ll assess as soon as the AS is gone, and then turn on final at EI minus 7.”
“Rog. Jeff, pyros?” said Abby.
“A and B armed. 25 seconds. God, I hate this part.”
“What part is that?” said Gabe.
“Well, this approach stage cost about $60 million, we used it for a bit over twelve minutes, and in fifteen or twenty minutes it’s gonna be just another Martian impact crater out in the middle of nowhere.”
“What did you want to do with it?” said Abby. “Take it home and put in on the mantle? 3, 2, 1, thrusting.”
“And… SEP!”
“There she goes.”
“I feel my checkbook’s pain.”
Abby laughed. “It’s only money, boss.”
“Right.”
“Okay, de-spin. Thrusting. 1.5, 1.0, 0.5, and… shutdown. Gabe?”
“Yes, we’re static.”
“ Alright, external balance mass jett.”
“EBM JETT,” said Jeff. “Gabe?”
“Confirmed. Two balance masses jettisoned. Standby for EI minus 9 state update… Star scanner and ground track confirm G&N position, attitude, flight path angle, and velocity. Computer is Go for Entry Interface. Ready for hypersonic aeromanuevering. Entry attitude maneuver in 2 plus 20.”
“Roger,” said Abby, “2:20.”
“Seven minutes,” said Gabe. “Abby?”
“Turning on final.” Abby turned the craft to ‘eyes in’. They were now flying backwards, the heatshield oriented down their flight path. “We’re there.”
“Roger. We’re in the corridor. Bank Attitude, HOLD.”
“HOLD.”
“Gabe, we’re not gonna run into the MRO, are we?” said Jeff.
“No, not even close. It’s approaching the South Pole, on it’s way to a daylight pass somewhere near Gale.”
“Rog. Just wondering if we should be watching for traffic.”
“At this altitude? Not likely. Nothing this low would stay in orbit for long.”
“Got it.”
“Why is that?” said Susan.
“Because it’s only mid-spring down there,” said Gabe. “In the summer the atmosphere heats up and expands. Anything orbiting at this altitude would eventually run into the upper atmosphere and, owing to friction, the orbit would begin to decay. And eventually, to use one of your favorite terms, splat: bug verses Martian windshield at 4,000 meters per second, and whatever isn’t incinerated upon entry gets scattered over a dozen kilometers in bite-size pieces.”
Susan groaned. “Thank you. Too much information.”
“You asked.”
“I did, didn’t I?”
“Uh huh.”
“Entry Interface,” said Gabe. “4,714 meters per second, altitude 3,522 kilometers radius, 569 kilometers to the landing site, four and a half minutes to chute deployment. Abby, 0.1 g’s. Bank Attitude, AUTO.”
“AUTO.”
It was an almost imperceptible bump, really just a tick, but Jeff felt it, and it wasn’t empty space.
“Atmosphere?” said Susan.
“Yeah.” Jeff didn’t want to be scared, but he was. And from the tone of her voice, he knew she was too. Then another tiny bump. Then several more. “Here we go,” he said with his best artificially stoic inflection. A few more seconds and the capsule began to shake a little. And then it began to shake a lot. They’d passed through the exosphere, the upper reaches of Mars’ atmosphere, fairly quickly. There wasn’t much there, just a few wisps where the last bits of atmospheric gas blended into the void of space, undecided about favoring gravity or vacuum. Now came the thermosphere, an unhappy place where high temperatures from solar heating cause the atmospheric gases to disassociate and create a cobblestone road of pressure pockets and random erratic thermals.
“EI plus 10 seconds,” said Gabe. “4,575 meters per second, altitude 118 kilometers. 1.5 g’s.”
Jeff closed his eyes and leaned his head as far forward as he could in the helmet. He didn’t know if there was a God, but at that moment he suddenly hoped that if there was, it was a merciful God. ‘Seven Minutes of Terror,’ that’s what they called it. That’s how long it took to get from low orbit to the ground, seven minutes.
“EI plus 22 seconds, 4,384 meters per second, altitude 109 kilometers. 2.6 g’s.”
He was certain it would be the longest seven minutes ever… for anyone, any time, any place. Unless of course it ended early, which would be worse. Four and a half kilometers per second, 9,950 miles per hour, headed into a place so inhospitable most people simply could not imagine it.
“EI plus 37 seconds, 4,154 meters per second, altitude 98 kilometers. 4.9 g’s. Oh god!”
But here he was, and there was no going back. He opened his eyes briefly and glanced at the HUD. Hundreds of hours of training for this moment and suddenly the numbers were just so much gibberish. He reached down, searched around briefly until he found Gabe’s hand, and tightly clasped it. “How are you doing?”
She whimpered. “I’m terrified.”
“Hang in there. How are we doing?”
“Um, EI plus 60 seconds, 3,820 meters per second, altitude 82 kilometers, 8.0 g’s. I can’t breathe.”
“Hang on! Abby?”
“Dead center in the corridor. One express elevator to Hell; goin’ down!”
Jeff wanted to laugh at Abby’s Aliens reference, but he couldn’t. As the lander bounced and jiggled like it was being jostled down a rocky riverbed, nothing was funny. Still, her voice was comforting, rather like she was issuing a traffic advisory. She was the most skilled pilot and the iron backbone of the crew. Were she the only one of them to survive, he figured she’d assemble the MAV alone and still make it home. He wasn’t so certain about himself.
Gabe cried, “Oh god! EI plus 80 seconds, 3,521 meters per seco
nd, altitude 67 kilometers, 11.0 g’s. Peak heat! Max pressure in five seconds.”
As the g-force continued to rise, Jeff found it more and more difficult to breath. And in spite of his suit’s cooling system, the cabin was getting awfully warm as the external temperature of the ablative heat shield approached 3,600ºF. The HUD was now difficult to read as his vision began to blur under the g-force. He thought it read 11.2 g’s, but wasn’t sure. They should reach peak dynamic pressure and 11.4 g’s momentarily, but supersonic chute deployment was still three minutes away. It was going to be a long three minutes. “Sue, how ya doin’?”
“Oh god! I think my boobs just popped out my back.”
Abby chuckled. “What boobs?”
“Jeff, smack her for me!”
“Later, I can’t lift my arm!”
“One minute thirty seconds,” screamed Gabe. “11.4 g’s! Max pressure! 53 kilometers, 3,228 meters per second, 2:52 to chute deployment!”
“Gabe!” yelled Susan. “You’re hyperventilating. Stop it!”
Gabe gasped. “How can I be hyperventilating? I can’t breathe.”
“You’re on pure oxygen, relax, breathe normally.”
“I can’t!”
“We’re banking!” said Jeff.
“Deadbanding cross-range error,” said Abby.
“Rog. How do we look?”
“Right down the pipe.”
“You sound awfully calm.”
“I’ve pulled 11 g’s before.” She groaned. “Oh! But not for this long.”
Jeff did everything he could to force his lungs to work. Exhaling was easy, inhaling was almost impossible. He panted, short breaths. Gabe’s hand went limp. “Gabe?” There was no reply. “Gabe!”
Susan squeaked, “She’s fainted.”
“Is she alright?”
“Yes, she’ll come around in a minute.”
“She never passed out in the centrifuge at 11 g’s.”
“We only got to that point momentarily, and it was on Earth. I don’t think she was afraid of dying there.”
“We need her. Is there anything you can do?”
“Strapped in here and encased in Mark III suits? No.”
“Rog. Abby?”
“What?”
“Where are we?”
“I dunno. All I’m looking at is our trajectory. Oh, crap. Hang on a minute… uh, yeah, um, two minutes forty, leveling out. G’s are dropping fast: 8.1, 7.9, 7.7… 2,332 meters per second, 14.5 kilometers altitude, and we’re still in the corridor.”
Gabe groaned. “Oh… god. What happened?”
“You fainted,” said Susan.
“Oh, my head hurts.”
“Just relax, breathe normally, you’ll be fine.”
“I can’t see straight. How long was I out?”
“About a minute. Just close your eyes, relax, and breathe.”
“Okay. Where are we?”
“Three plus fifty,” said Abby. “1,300 meters per second, about 10 kilometers altitude, in the corridor, but maybe a couple klicks northwest.”
“Okay. At 1,100 meters per second, transition to alignment phase.”
“Yeah, I got it. Transitioning.”
“Gabe, you okay?” said Jeff.
“Yeah, I think so. Sorry. Balance mass jett in 25 seconds.”
“Rog. Don’t worry about it. We’re doing fine.”
“Pyros, ARMED.”
“ARMED,” said Jeff.
“20 seconds. 35 seconds to chute deployment. Based on position data from Pathfinder, looks like we’ll touchdown about 020º 15 kilometers from the station. Abby, watch out for those hills to the west.”
“Not much I can do about it now, we’re pretty much ballistic.”
“Bank us up and delay balance mass jett and chute deployment by two seconds.”
“You sure?” said Jeff.
“Yes.”
“Rog. Abby, do it.”
Abby grabbed the RCS joysticks. “Pitching.”
“Five seconds,” said Gabe. “And… jett.”
Jeff punched the jettison button and the six entry balance masses on the wind side of the hull just above the heat shield joint were explosively discharged, returning the craft to a fully balanced state.
“Rog. I gave the computer a +2. PROCEED.”
“PROCEED,” said Jeff.
“10 seconds.”
“Sure glad you didn’t decide to sleep through this part.”
“Me too. 5 seconds… 3, 2, mach 2.05”
Jeff felt the jolt as the mortar-deployed parachute was ejected. “Ouch.” As the chute opened, the craft suddenly decelerated.
“Oh god!” cried Gabe.
Jeff groaned. “Yeah. That’s like driving into a brick wall at 70 miles an hour. How much was that?”
“Nine g’s. 15 seconds to heatshield jett. 300 meters per second, 9 kilometers. Anticipate touchdown 16 kilometers north of the station.”
“Good job,” said Jeff. “Close enough.”
“10 seconds… 5, and… heat shield jett.”
The lander momentarily lurched upwards as the 840-pound heat shield detached and fell away.
“We’ve got radar,” said Gabe. “145 meters per second horizontal, 6.9 kilometers altitude. 68 seconds to backshell jett. MARDI activated.”
“You have an image?” said Jeff.
“Yes. I think we’ll be fine. North of the ellipse center, but in the flat.”
“Excellent. You gonna tell Amos to pick us up at the airport?”
“Already on his way.”
“Rog.”
“15 seconds. 120 meters per second horizontal, 2.5 kilometers altitude. 10 seconds… 5, and… backshell and chute jett.”
The lander dropped suddenly then stabilized as the eight engines of the descent stage throttled up.
“Powered descent,” said Gabe. “One kilometer altitude, 84 meters per second vertical, 24 horizontal. 40 seconds to touchdown.”
“Rog. How’s the ground look?”
“Looks good. Just what we saw from all of the Amos and Andy imagery. 22 seconds to Sky Crane.”
“I wonder what everyone on Earth is thinking right now?”
“They’re thinking we’re still in space. What they’re seeing happened 9 minutes ago.”
“Oh, yeah, forgot about that.”
“8 seconds. 5, and… Sky Crane. Descent stage is in hover at 35 meters and we’re descending.”
“By god, it worked!”
“Oh, thank god! 3 meters per second descent, horizontal travel is static. 10 seconds to touchdown. One meter per second vertical. 5 seconds. Here comes the ground!”
Thursday, October 6, 2016
MSD 50750.392 (Sol 0)
“Oof!” said Jeff as the lander impacted on the Martian surface. “That was a little harder than I thought it would be.”
“Bridle SEP and flyaway,” said Gabe. The three umbilicals of the Sky Crane were separated from the lander by an explosive cutter and the descent stage throttled up and flew off to crash half a mile away.
Abby sighed aloud. “I think I’m supposed to say touchdown, but, um, it seems redundant.”
Jeff laughed softly. “Uh huh. Okay, we’re here. Everybody alive?”
“Yes,” said Susan.
Jeff waited a moment, but there was no response from Gabe. “Gabriel, are you alive?”
She whimpered. “Yes. I think so.”
“Well, you think, therefore you are.”
She sniffed. “Descartes could have been wrong.”
He chuckled. “Yeah, I suppose. But for now, let’s take that one on faith. Okay?”
“Okay.”
“Alright then. You have an ETA for Amos?”
“About fifteen minutes… traffic permitting.”
“Okay. Well, that was the longest seven minutes of my life.”
“Amen to that,” said Abby.
“What say we all sit back for a minute and catch our breath. Did anybody note our touchdown time?”
<
br /> “Yes,” said Gabe, “2:04:19 UTC.”
“Thanks.” After a moment he chuckled.
“What?”
“Oh, I was just thinking… we’re on Mars, and we’re alive. We made it.” He took Abby’s hand and reached down between their couches to Gabe and Susan. They all held hands in silence for a minute.
Gabe squeezed his hand. “Oh my god.”
“What?”
“Gravity.”
“Yeah.”
“Finally!” said Abby. “Now maybe this puffiness in my face will go away and I can stop blowing my nose every five minutes.”
Jeff chuckled. “Right. Well, shall we open the door and have a look around?”
“By all means.”
“Okay. Pyros A and B armed and…” Jeff heard a soft ‘bang’ as explosive bolts separated the upper crew compartment aeroshell. “SEP.” He and Abby pushed up on the aeroshell, walked it hand-over-hand to the forward end of the crew module, and tossed it on the ground. Jeff raised his head and glanced around. “Oh my god.”
“What?” said Gabe.
“Well, Toto, we’re not in Kansas anymore.”
“No kidding? Hurry up, I want to see.”
“Uh, yeah. Just give me a minute, I’ve waited a long time for this.”
Abby grabbed his hand. “Boss, go put your footprints on Mars.”
He glanced at her and returned the smile he saw through her helmet face shield. “Yeah, okay.” He slapped his harness quick disconnect, switched on his helmet camera, gingerly stood in his couch, looked around again, and laughed. “I don’t believe it! We made it! We’re here! Earth, mankind has arrived on Mars!”
Abby joined his laughter. “Womankind also.”
“Yeah, them too.” He turned around, sat on the edge of the lower aeroshell, slowly spun around, and slipped off onto the surface. “Whoa!”
“What?” said Abby.
“Um, in spite of our exercise routine in transit, standing takes a bit of getting used to.” He carefully took a few steps and stopped, taking in the view: burnt orange sky, dark grayish-red sand, scattered rocks, an outcropping here and there, but otherwise nearly featureless to the horizon in all directions. “Wow. Not much here. Looks a lot like Opportunity’s images of the Meridiani Planum.”
“That’s why we picked it,” said Gabe.
“Yeah. Abby, your beach, palm trees, and five-star resort must be someplace else, cause they’re not here.”
Margaritifer Basin (Margaritifer Trilogy Book 1) Page 72
