Roman Space Telescope Mission Could Last Up to 22 Years Due to Fuel Savings

NASA's Nancy Grace Roman Space Telescope, which has not yet reached its planned orbit around the Sun-Earth system's second Lagrange point (L2), has been given a significantly longer mission outlook. Thanks to fuel savings during the initial flight phases, the probe is capable of conducting scientific observations for 22 years.

The original plan called for five years of initial observations, followed by another five years of extended mission. Now, the total mission duration could reach 22 years.

Jamie Dunn, Director of NASA's Goddard Space Flight Center, stated that 'thanks to our team's exceptional orbital dynamics planning, the brilliant execution of the operations team, and the precise launch by SpaceX, Roman has enough fuel for potential scientific operations for at least 22 years.'

Alison Rao, who is responsible for Roman's propulsion system at Goddard, explained that because Roman's mass turned out to be less than calculated, they were able to fill the fuel tanks to maximum capacity instead of just what was needed for the ten-year requirement.

The difference was substantial: the 2015 reference document assumed a total spacecraft mass of 4,166 kg, using only 107 kg of fuel. Later, as the project evolved, the projected mass increased to 9.8 thousand kg. However, upon launch, Roman weighed 8,056 kg. Since there was extra space in the tanks, the lower mass allowed for more fuel to be loaded.

According to the mission resource study, this extra fuel can provide about four additional years of observation.

Another gain came from the first trajectory correction after launch. The maneuver took place on August 31st and was completed with over 99% accuracy. In addition to high accuracy, it also benefited from the spacecraft's lower weight. During the correction, which lasted about three minutes, NASA used only 18 kg of fuel against a planned 200 kg, which is less than 10% of the initially reserved amount.

The next trajectory correction is also expected to consume less fuel than planned because the first maneuver was so accurate. The final phase of the flight should also contribute to savings. It is planned that Roman will be placed into a halo orbit around L2 in early December, and NASA expects this maneuver to also require less fuel than originally anticipated.

After reaching orbit, the telescope will only need periodic small burns to maintain its trajectory, approximately every 28 days. Collectively, these factors could provide about 12 additional years of observation.

More Details:

The first five years of the mission will primarily be dedicated to Core Community Surveys, including the High-Latitude Time-Domain Survey.

The five years originally planned for the extended mission will be devoted to the General Observer (GO) program, which provides observation opportunities for a wider community of astronomers and astrophysicists. About 50 applications have already been prepared for the GO program. NASA has not yet announced how the approximately 12 additional years of observation will be utilized, but the program should cover a significant portion of this period. Major research may also receive additional time.

Roman is still equipped with a coronagraph—an instrument that serves as a technology demonstrator for a future planet-hunting mission. If the equipment shows good results, it may also be used during the additional years of the mission.

The telescope was originally named WFIRST (Wide-Field Infrared Survey Telescope) but later received the name Nancy Grace Roman in honor of the first director of NASA astronomy. Initially, the project envisioned a 1.5-meter mirror, but during development, the telescope received a 2.4-meter mirror, which was originally designed for an observation satellite. After many years of project changes and discussions regarding funding and scientific goals, Roman is approaching the operational phase.

Upon arrival at L2, the spacecraft will undergo commissioning and testing before beginning scientific observations. The article about the Roman Telescope potentially doubling the mission duration and remaining in space for 22 years for the first time appeared in Olhar Digital.

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olhardigital.com.brSeptember 3, 23:49

Project plans to launch a space probe for 800 years: historical breakthrough or technological illusion?

A small spacecraft could be launched toward Alpha Centauri, the closest star system to the Sun, on a journey that would take about 80 thousand years. The proposal, named Fermi Explorer, intends to use existing technologies to demonstrate the possibility of an interstellar mission, even a very slow one, without relying on futuristic propulsion systems or billion-dollar investments.

This idea was presented on Tuesday (1) by mathematician and physicist from the UK, Philip Johnston, and other entrepreneurs. The group plans to raise $15 million (about 76.6 million Brazilian reais) to build a probe with a payload of only 1 kg and attempt to launch it in 2029. Instead of aiming for a fast arrival, the project is betting on a low-cost strategy for placing the spacecraft on a path to another star.

Discussion of Mission Goals

In an interview with Olhar Digital, Roberto Dias da Costa, Associate Professor at the Department of Astronomy at IAG-USP and director of CienTec, explained that the mission's goal is not an isolated star like our Sun. He clarified that Alpha Centauri is a triple system consisting of two stars very similar to the Sun, named Alpha Centauri A and Alpha Centauri B, and one red dwarf known as Proxima Centauri, which is significantly smaller.

According to the astronomer, the two larger stars are separated by 23 astronomical units (AU), equivalent to the distance between the Sun and the planet Uranus, and are located 4.36 light-years from Earth. The third star orbits this pair at a much greater distance, being the closest to our planet. 'Proxima is significantly farther from the pair, currently about 12 thousand AU away from them, and is located 4.24 light-years from us, making it slightly closer.'

Despite being our nearest stellar neighbor, the distance is so vast that a conventional ship would take thousands of years to cover the journey. Fermi Explorer will travel at a speed of approximately 25 km/s, which is enough to escape the Solar System but too little compared to the distances between stars. As a result, the journey will take about 79,800 years.

This means that if the mission is launched in 2029 and completes its route, arrival will occur around 81,829! None of the project participants will be alive to see the result. In fact, thousands of generations will pass between launch and arrival. Thus, the spacecraft will function as a kind of technological capsule sent into such a distant future that the modern world will be unrecognizable.

Acceleration Mechanism

The challenge begins long before the probe leaves the Solar System. Fermi Explorer will first be launched into a low Earth orbit, likely as part of a joint launch mission. Then, a long series of maneuvers around the Sun will begin. Instead of simply directing the craft toward Alpha Centauri, the developers intend to use the star itself as part of the mechanism to accelerate the probe.

For over ten years, the probe will execute carefully calculated orbits, gradually approaching the Sun. The point of closest approach may reach 0.42 astronomical units, or about 62.9 million kilometers, which is slightly less than half the average distance between the Earth and the Sun. In this region, solar radiation is much more intense, allowing panels to generate more energy to power an electric propulsion system.

The team plans to combine these close passes of the Sun with the so-called Oberth effect, a phenomenon that allows for better utilization of engine thrust when the spacecraft is moving at high speed. Multiple such maneuvers, called 'perihelion boosting,' will gradually increase the probe's speed until it can finally leave the Solar System.

However, according to Costa, the strategy adopted by the private group does not represent a major aerospace breakthrough. 'They say it is a technology test, but I believe it will only serve as a check of the 'elastic band effect,' which involves placing the probe in an orbit that allows it to pass close to a very massive body, in this case the Sun, and thus gain speed. But this is in no way new; many probes have already used this technique.'

According to an 81-page technical assessment prepared with the help of artificial intelligence, this solar acceleration process could take about 12 years. After this, Fermi Explorer will continue moving almost purely by inertia toward Alpha Centauri. A speed of about 25 km/s will be sufficient to start the journey, but not to make it fast. Most of the 80 thousand years will be spent in deep interstellar space.

The mission is not intended to carry people or even a large number of scientific instruments. The priority is to test whether a very small spacecraft can undertake such a journey using relatively simple components. Nevertheless, without active propulsion after the initial phase, the astronomer from IAG-USP emphasizes the problem of trajectory accuracy. 'Since this hypothetical probe has no directional control and will move only by inertia, I believe it is impossible to 'accurately target' one of the three stars in the system.'

After the initial stages, communication will become an issue. Direct contact will last about 18 months, while reflectors will help ground telescopes track the craft for some time. However, once it crosses Jupiter's region, Fermi Explorer will become increasingly difficult to detect, silently advancing for tens of thousands of years. There will be no team waiting for arrival, and there will be no rescue mission. The probe's fate will be to continue its trajectory until reaching the Alpha Centauri system.

Additional Remarks

Signal loss at such an early stage is one of the most criticized aspects by experts. 'If they themselves say they will lose the ability to track the probe when it is about the distance of Jupiter, then anything beyond that will just be speculation. Note that Voyager 1 and 2 were launched in 1977 and are still operating! They are now more than 150 times farther from the Sun than Earth! Jupiter is only 5 times farther from the Sun than us,' analyzes Costa.

As unlikely as it may seem, the 80,000-year journey has a purpose that goes beyond simply reaching another star. Johnston links the project to the Fermi paradox, which questions why, despite the vast number of existing stars and planets, we have yet to find convincing evidence of other civilizations. One possible reason is that interstellar travel is too complex for any form of life.

Fermi Explorer would be a way to test exactly this hypothesis. If a technological civilization can send a small spacecraft to another star using relatively modest resources, even if it takes tens of thousands of years to arrive, one of the potential obstacles of the paradox weakens. The mission would also leave a message for the extremely distant future: humanity was able, at least, to attempt to cross the space between stars.

The project is still far from guaranteed realization. The team needs to secure funding, build the spacecraft, find a suitable launch, and execute a complex sequence of maneuvers. Even if all these stages are completed, the mission will remain a bet with an almost incomprehensible timeframe.