Space Sunday: Juno, Orion and getting to Mars

An artist's impression of Juno orbiting Jupiter (Nasa JPL)
An artist’s impression of Juno orbiting Jupiter (Nasa JPL)

Juno is the name of the NASA deep space vehicle due to rendezvous with Jupiter in July 2016. Launched August 5th, 2011, from Cape Canaveral Air Force Station, the mission is designed to study Jupiter’s composition, gravity field, magnetic field, and polar magnetosphere, as well as seeking evidence and clues on how the planet formed, including whether it has a solid core, the amount of water present within the deep atmosphere, how its mass is distributed, and its deep winds, which can reach speeds of 618 kilometres per hour (384 mph).

Unlike most vehicles designed to operate beyond the orbit of Mars, which tend to utilise radioisotope thermoelectric generators (RTGs) to produce their electrical power, Juno uses three massive solar arrays, the largest ever deployed on a planetary probe, which play an integral role in stabilising the spacecraft.

On arrival at Jupiter on July 4th, 2016, Juno will enter a 14-day polar orbit around the planet, where it will remain through the duration of the mission, which should last until February 2018, when the vehicle, fuel for its manoeuvring systems almost depleted, will be commanded to perform a de-orbit manoeuvre and burn-up in Jupiter’s upper atmosphere.

Juno's journey
Juno’s journey (image: NASA)

Currently travelling at some 25 kilometres per second relative to the Earth and 7.6 kilometres per second relative to the Sun, Juno has used a 5-year gravity assist mission to reach its destination.

The first part of this saw the craft launched into an extended orbit about Earth which carried it beyond the orbit of Mars (2012), before swinging back to make a close flyby of Earth in 2013 which both used Earth’s gravity well to accelerate the craft and as a “slingshot” to curve it onto a trajectory that would carry it to Jupiter.

By the time Juno enters orbit around Jupiter, it will have travelled some 2.8 billion kilometres (1.74 billion miles, or 18.7 AU).

Juno’s planned polar orbit is highly elliptical and takes it to within 4,300 kilometres (2,672 mi) of either pole at its closest approach to the planet, while at its furthest point from Jupiter, it will be beyond the orbit of Callisto, hence the 14–day orbital period. This extreme orbit allows Juno to avoid any long-term contact with Jupiter’s powerful radiation belts, which might otherwise cause significant damage to the vehicle’s solar power arrays and electronics. Overall, Juno will receive much lower levels of radiation exposure than the Galileo mission. But even allowing for this, there is no guarantee the exposed science instruments on the vehicle will last the full duration of the mission. Scientists and engineers are hoping the JunoCam and Jovian Infra-red Auroral Mapper (JIRAM), will last at least eight of the mission’s 37 orbits of Juptier, and that the microwave radiometer will survive for at least eleven orbits.On Wednesday February 3rd, 2016, the vehicle completed the first of two final manoeuvres designed to correctly align it with its intended point of orbital insertion around Jupiter. The second such manoeuvre will take just before Juno is due to arrive at Jupiter.   The spacecraft’s name comes from Greco-Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, but his wife, the goddess Juno, was able to peer through the clouds and see Jupiter’s true nature – just as it is hoped the mission will probe deep into the planet’s atmosphere and reveal its true nature and origins.

Orion at Kennedy Space Centre

Now set for launch in September 2018 on a circumlunar mission lasting 20 days, the second Orion space vehicle arrived at Kennedy Space Centre, Florida, on Wednesday, February 3rd, 2016. The vehicle, sans its outer skin and massing 1.22 tonnes, arrived from NASA’s assembly facility iin Louisiana by air aboard the agency’s “Super Guppy” transporter, which has been transporting space vehicle components since the Apollo era.

Further construction activities and a variety of tests will be performed at KSC and NASA’s Glenn Research Centre in Ohio to prepare the craft for its mission, officially titled Exploration Mission 1 (EM-1). This will see the uncrewed Orion launched for the first time with and operational, European-built Service Module atop its dedicated Space Launch System (SLS) rocket.

A European Orion Service Module having the launch payload fairings attached to it. The Orion vehicle is attached to the circular part of the Service module visible at the top. This was a structure flight test article used in Orion's first test flight in December 2014 (image: Airbus / ESA)
A European Orion Service Module having the launch payload fairings attached to it. The Orion vehicle is attached to the circular part of the Service module visible at the top. This was a structure flight test article used in Orion’s first test flight in December 2014 (image: ESA / NASA)

“This mission is pretty exciting to us,” Scott Wilson, NASA’s Orion production manager, said as the capsule arrived at KSC. “It is the first time we will have the operational human-rated version of Orion on top of the SLS rocket. It’s a lot of work, but a very exciting time for us.”

The flight will see the Orion system launched into Earth orbit, where a purpose-built upper stage propulsion unit will power the craft onto a flight towards the Moon.

Orion will use the relatively low lunar gravity to both accelerate it and throw it into an elliptical orbit, carrying it a further 70,000 kilometres beyond the Moon – almost half a million kilometres (312,500 miles) from Earth – further than any space vehicle designed to carry humans has yet flown.

Following this, the vehicle will swing back towards Earth, passing the Moon once more before the Command Module separates from the Service Module to make a controlled entry into Earth’s atmosphere and a splashdown in the Pacific Ocean.

The flight will be a comprehensive test of the European-built Service Module, which is vital for providing power and propulsion to the Orion capsule, and which is being built using  the expertise Europe gained in building and operating the Automated Transfer Vehicle, which remains the largest ISS resupply vehicle so far used in space.  The Service Module includes four post-launch deployable solar panels for electrical power, and provides power, heat rejection, the in-space propulsion capability for orbital transfer, attitude control and high-altitude ascent aborts. It also houses water, oxygen and nitrogen for deep space missions.

Like the Apollo Command and Service modules vehicles, the Orion capsule sits on top of the Service Module at launch, covered by the launch abort system shroud, the service Module protected by special payload fairings and mated to the SLS upper stage propulsion unit. The launch abort system and the fairings are jettisoned once the Orion has reached low Earth obit and has separated from the rest of the SLS booster. The Service Module solar panels are then deployed, and the upper stage of the booster re-fires, sending Orion on its way.

The 2018 mission will be followed in 2023 by a similar flight, this time carrying a crew of four further into space than any humans have ever previously been. Together, Orion and the SLS are intended to be the backbone of America’s return to the moon and for human missions to Mars.

Congress Wants More from NASA on Humans to Mars

As the US Presidential elections loom, members of Congress have called on NASA to refine its human exploration plans in order to better survive the transition from one administration to another,  while also defending two key elements of those plans.

The goal of landing humans on Mars has, in many respects, been at the heart of US space endeavours. Even before the first object had achieved orbit around this planet, Werner von Braun published Das Mars Projekt in 1953, setting out a vision for sending humans to Mars. During the 1950s, 60, and 70, NASA continued to invite proposals and ideas for sending humans to Mars, and in 1989, in response to President George H.W. Bush, went so far as to publish its own “grand plan” for getting humans to Mars – at a cost of some US $500 billion and a 30-year time frame; something no US Administration or Congress would sanction.

Not a lot has changed in the intervening years; even now, the means by which NASA will actually undertake a human mission to Mars isn’t clear. It’s bound up with returns to the Moon, missions in cislunar space, such as the Asteroid Redirect Mission (which actually contributes next to nothing to a mission to Mars), and so on.

NASA's Journey to Mars, the latest iteration of their vision for sending humans to Mars is big on concepts and ideas, light on hard facts such as costs and time scales. Congress see this as a weakness which could see hopes of getting humans to Mars any time soon squashed by future presidential administrations and / or Congressional sessions
NASA’s Journey to Mars, the latest iteration of their vision for sending humans to Mars is big on concepts and ideas, light on hard facts such as costs and time scales. Congress wants NASA to put more meat on their ideas (image: NASA)

Congress is therefore concerned that unless the space agency starts specifying just how it intends to use hardware such as Orion and its new launch vehicle, the Space Launch System, to get humans to Mars, and present something to Congress that can be supported and acted upon, there is a real risk that the ideal of sending humans to Mars will remain a pipe dream forever at risk of budgets cuts or complete programme cancellation – possibly starting with the incumbent in the White House.

Edgar Mitchell

Astronaut Edgar Mitchell, Lunar Module pilot on Apollo 14, passed away Thursday in West Palm Beach, Florida, on the eve of the 45th anniversary of his lunar landing.

Edgar Mitchell photographed in 1971 before the Apollo 14 mission graphic (image: NASA)
Edgar Mitchell photographed in 1971 before the Apollo 14 mission graphic (image: NASA)

Mitchell joined Apollo 14 commander Alan Shephard, Junior, the first American in space, in the lunar module Antares, which touched down February 5th, 1971 in the Fra Mauro highlands.

Shepard and Mitchell were assigned to traverse the lunar surface to deploy scientific instruments and perform a communications test on the surface, as well as photograph the lunar surface and any deep space phenomena. It was Mitchell’s only spaceflight.

He was drawn to NASA’s manned spaceflight programme by President Kennedy’s call to send astronauts to the moon. “After Kennedy announced the moon programme, that’s what I wanted, because it was the bear going over the mountain to see what he could see, and what could you learn, and I’ve been devoted to that, to exploration, education, and discovery since my earliest years, and that’s what kept me going,” Mitchell said in 1997 interview for NASA’s oral history program.

“To me, that (spaceflight) was the culmination of my being, and what can I learn from this? What is it we are learning? That’s important, because I think what we’re trying to do is discover ourselves and our place in the cosmos, and we don’t know. We’re still looking for that.”

Mitchell and Shephard set mission records for the time of the longest distance traversed on the lunar surface; the largest payload returned from lunar surface; and the longest lunar stay time (33 hours). They were also the first to transmit colour TV from the lunar surface. Mitchell helped collect 94lbs of lunar rock and soil samples that were distributed across 187 scientific teams in the United States and 14 other countries for analysis.

In his book “The Way of the Explorer”, he wrote, “There was a sense that our presence as space travellers, and the existence of the universe itself, was not accidental but that there was an intelligent process at work.”

Astronaut Edgar D. Mitchell, Apollo 14 Lunar Module pilot stands by the deployed U.S. flag on at the Frau Mauro landing site on February 5th, 1971. He was photographed by astronaut Alan B. Shepard Jr., mission commander. While astronauts Shepard and Mitchell descended in the Lunar Module "Antares" to explore the Fra Mauro region of the moon, astronaut Stuart A. Roosa, command module pilot, remained with the Command and Service Module "Kitty Hawk" in lunar orbit.
Astronaut Edgar D. Mitchell, Apollo 14 Lunar Module pilot stands by the deployed U.S. flag on at the Fra Mauro landing site on February 5th, 1971. He was photographed by mission commander Alan B. Shepard Jr., standing alongside the  Lunar Module Antares. The third member of the Apollo 14 mission, Stuart A. Roosa, Command Module pilot, remained with the Command and Service Module Kitty Hawk in lunar orbit.

In a statement released when news of Mitchell’s passing broke, NASA Administrator Charles Bolden, himself a former astronaut of the shuttle era, said, “On behalf of the entire NASA family, I would like to express my condolences to the family and friends of NASA astronaut Edgar Mitchell. As a member of the Apollo 14 crew, Edgar is one of only 12 men to walk on the moon and he helped to change how we view our place in the universe. “