Part of USS Arcturus: Paradise Found

The Oberth Effect

USS Arcturus, Main Bridge
November 2399
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Ten minutes later, Timothy Marshall’s leg was bouncing as he waited for the order to go, a habit he’d never quite been able to shake. The newly-minuted lieutenant commander was ready to see what the Arcturus could do, and he was champing at the bit to get out into open space. Next to him, the ship’s operations officer put in the final commands to separate the Arcturus from the transport that had brought Marshall and the Vulcan ship. He’d gone straight from reporting in with the first officer to assume his station, so there hadn’t been a chance for introductions yet, so all Marshall knew about his colleague was that he had large, brown eyes and olive-toned skin.

“Umbilicals retracted, Captain. Both ships are now moving off,” the operations officer reported. “We’re clear to maneuver.”

“Course-heading, sir?” Marshall asked, turning around to offer a broad smile to Captain Lancaster, who was sitting with his legs crossed in the center seat, flanked by the first officer and the senior officer of the watch, Commander Song.

“When’s the last time you performed an Oberth maneuver, Mister Marshall?” Lancaster asked, prompting the two officers sitting next to him to look at him and then each other in surprise.

“A powered fly-by? A real one? Not since the Academy, sir. With modern impulse–,” Marshall started before Lancaster held his hand up. 

The Oberth effect was why gravity assists worked: a spacecraft can go faster than the force of its propulsion systems would allow for when accelerating towards an object with sufficient mass. Marshall had done it several times with Sparrow-class trainers at the Academy, but in modern space travel, it was rarely done. Impulse engines did not move the ship solely through the propulsive force of their exhaust, but using subspace driver coils that reduced the ship’s mass sufficiently to allow for comparatively small amounts of thrust to move the ship much faster than would be permissible under ordinary physics, and which compensated for the time dilation effect one would typically experience at close to half the speed of light. 

“I’m aware of how impulse drive works. Are you saying you can’t do it?” the captain asked. 

“No, sir. I can execute any order you give me,” Marshall replied, not batting an eye at the challenge. 

Marshall did not consider himself particularly good at registering other peoples’ motivations; his brain was wired to take people at face value. That being said, he knew he was being tested, and if it weren’t speaking out of turn, he’d have told the captain, “Bring it on.”

“Your service record tends to agree, but let’s test that,” Lancaster said. “Bridge to Engineering. Disable the subspace driver coils and configure the impulse engines for purely propulsive flight,” he ordered.

There was a slightly longer pause than Marshall would expect before the response came.

“May I ask why, sir?” a female voice asked.

“You heard the order. We’ll be leaving orbit shortly. Bridge out,” Lancaster replied, closing the channel with his thumb on the intercom button. “Mr. Marshall, switch to manual control.”

“Aye, Captain,” Marshall replied, tapping in the command to override the computer’s automatic course correction.

After a moment, a few indicators changed on Marshall’s station to indicate the altered capabilities of the ship’s main engines. Without the engines in their standard configuration, a quick estimate of power to mass ratios told him that they would actually need the Oberth effect to get out of orbit, rather than it just being a stunt.

“Engines reconfigured, Captain,” the operations officer reported. “Though, I feel obligated to point out that if our course is off by even a few degrees, we will crash into the planet.”

That comment made Marshall bristle, his jaw clenching as he laid in the course on his station. It was a basic maneuver, even if it wasn’t one he’d performed recently. With the mass of the ship, the mass of the planet, and the available acceleration all being known quantities, it was a simple matter to figure out the angles and timing required.

“Noted, Commander. Helm, show me what you’ve got,” the captain ordered.

“Aye, Captain,” Marshall replied before cracking his knuckles. “Executing bi-elliptic transfer in preparation for gravity-assisted departure.”

The helmsman kept his attention split between his station and the viewer in front of them, watching as the ship began to pick up speed, the raw thrust from the engines pushing them out from a circular orbit to an elliptical one, which momentarily brought the viewer away from the planet. Monitoring their speed to ensure that they were gaining enough momentum, he kept the ship on course with the lateral thrusters.

With consistent power, the ship accelerated through its first orbit in an excruciating five minutes, the bridge watching Marshall in silence except for occasional updates from the operations officer. The following rotation was even faster, and that’s when Marshall shifted into the escape maneuver. 

“Executing gravity assist,” Marshall announced, lowering the ship’s bow.

On the viewer, it appeared as though they were going to crash into the planet, the atmosphere looming larger and larger until Marshall successfully executed the break-away burn after they’d picked up their maximum possible acceleration. The clouds and icy surface of the planet swam past the viewer and were replaced with the blackness of space. 

“Maneuver complete, Captain. We have left orbit,” Marshall reported, looking over his shoulder to cast a well-deserved smirk towards the man in the center seat.

“Well done, Mr. Marshall,” Lancaster replied with a nod. “Plot course to the Omicron Torrensis system. Warp 6.”

“Aye, Captain!” Marshall replied.

As he turned back around, Marshall noticed that the operations officer had the warp field controls brought up on his station. Establishing a low-level warp field would have enabled the engines to push the ship out of orbit without the subspace driver coils. It would have been necessary if Marshall had miscalculated. Talk about a lack of faith.

“Course plotted,” Marshall announced.

“Execute,” Lancaster ordered, prompting Marshall to engage the warp drive to take them to their next generation. “Commander Song, you have the bridge. Let beta shift have their stations back,” he ordered, almost as soon as the ship went to warp.

That announcement was followed moments later by the crew, who would generally be on the bridge during that time of day to relieve the senior officers, who’d been summoned just for the ship’s departure. Marshall followed the operations officer out of the bridge through the starboard exit and into a turbolfit car.

“Deck 8,” they both said at the same time.

“Thanks for the vote of confidence back there,” Marshall said, not wanting to start a fight but also not being one to back down very quickly when insulted.

“Larus Alesser,” the other man said.

“Well, Larus Alesser to you too…,” Marshall replied, confused; he didn’t know that language.

“No, it’s my name,” Alesser clarified, shaking his head. “All I know about you is that you’re amongst a legion of pilots on this ship with pretty faces. I won’t jeopardize the safety of the ship to sate your ego. It’s nothing personal.”

Marshall nodded, chewing on his bottom lip for a moment. The comment about his looks hadn’t gone unnoticed and did mollify some of his annoyance, though he often wished that people could find a compliment about something else for him.

“Timothy Marshall,” Marshall replied, extending his hand, which Alesser accepted with a very firm grip. “I guess that’s all I know about you, too.”

Alesser laughed. “Well, if we’re going to be sitting next to each other, we’ll have to change that. Are you going to the reception later?” he asked.

“Yeah, it didn’t seem optional,” Marshall replied. 

“Well, we can get better acquainted there, then,” Alesser noted, with a wink as the turbolift doors opened. “Shame. My quarters are on the opposite side from yours, so we’ll have to continue this later,” he said, pointing his thumb toward the port side. “Welcome aboard, by the way.”