OGDEN — As part of Engineer Week at Hill Air Force Base the last week in February, astrodynamics consultant Dan Adamo spoke on Feb. 24 at Weber State University about designing a realistic Mars mission trajectory.
Through a series of physics equations, Adamo explained just how complicated it is to get a spacecraft from Earth to Mars, starting with determining the best time to leave Earth. As an example, Adamo showed how departing Earth for Mars in early 2030 requires much more propellant and a much closer approach to the sun than delaying departure about a year.
“If you were to try to launch to Mars the first day in 2030, Earth is quite a distance away in orbit, so you would get to Mars, but it would be a close solar fly-by, and you’d go across the solar system and since we don’t have warp drive yet like “Star Trek’s” Enterprise, it just doesn’t work out,” Adamo said.
The next issue factored into a flight to Mars, Adamo said, involves the tricky nature of gravity and orbital pulls near planets. “You have to figure just how fast you’ll be going at Mars’ arrival and, with the gravitational pull of Mars, you will slingshot around it if you don’t have some kind of aero braking or propulsion to get into the planet’s orbit,” Adamo said. “This particular problem requires a number of steppingstones before we can … send humans. We do this with robots all the time, but so far it has eluded us for humans, because crewed spacecraft are more massive and harder to accelerate and this gives you an intuitive feel on why it’s so hard,” Adamo said.
It gets even more mind-boggling when engineers have to determine how much propulsion and speed to use for various parts of the trip. “The trade between time of flight and the changes in velocity is what makes us really have to regard Mars soberly. It is not an easy problem for massive human spacecraft,” Adamo said.
Adamo related how India just sent its first spacecraft to Mars for an orbiter mission, but scientists didn’t have a rocket that was strong enough to depart Earth with a single maneuver, so they did it one step at a time. Starting in a slightly elliptical orbit, they progressively increased its maximum distance from Earth until they finally provided the last rocket engine with enough energy to escape Earth’s gravity field. “It took them many weeks to leave Earth, but that was a part of their plan and now they are orbiting around Mars,” Adamo said.
Adamo warned audience members about the schemes of people claiming they can launch and take people one way to Mars.
“They must be studying a different physics than me because going out to Mars is just huge, especially when it comes to keeping them shielded from cosmic radiation and the massive amount of food you need for 900 days,” Adamo said. “You want short transit times because the crew is going to fry out there, but it’s going to cost more and you would need warp drive, which doesn’t exist outside of the entertainment industry yet. Unfortunately, you hear more than 200,000 people want to fly to Mars one-way, which irks me because it is the celestial equivalent of a Ponzi scheme.”
A round-trip flight time from Earth to Mars is approximately 900 days, and radiation protection is a big factor in getting humans to Mars. Currently, flight standards say astronauts shouldn’t suffer more than a 5 percent elevated risk of cancer in their lifetime.
However, Adamo says NASA may be in the process of revising that standard; scientists may need to lower the bar on required radiation shielding mass so astronauts can do the missions to Mars at less expense.
As always, budget is a concern, since funding a flight to Mars is massively expensive.
“If Congress won’t give NASA additional budget, we will be left with a program that can get us out into deep space, but can’t land in a deep gravity well, which includes the moon,” Adamo said.