Space Sunday: getting ready to fly on Mars

An art’s impression of the Ingenuity helicopter on Mars. Credit: NASA

If all goes according to plan, on Thursday, April 8th, we could be witnessing the first powered flight of an aerial vehicle on another planet as the blocky Ingenuity helicopter, part of NASA’s Mars 2020 mission, takes to the air for the first of what should be at least five proof-of-concept flights.

The helicopter itself is not a particularly exciting thing to look at: a cube-like fuselage no more than 20 cm across on its longest side that contains the vehicle’s avionics, a heater system to keep the sensitive circuitry warm and operating, a battery system to provide energy to the headers and the vehicle’s propellers, and its science systems. It is supported by four spindly legs just 38 cm long, and is topped by a mechanism of two contra-rotating co-axial rotor systems measuring 1.2 metres from tip-to-tip, with the main communications antennae above them, topped by the solar panels hat will be used to recharge the vehicle’s batteries.

Ingenuity and its systems. Credit: NASA

However, looks can be deceptive. Ingenuity is actually a highly capable aircraft and spacecraft combined. Its systems were designed to withstand 6+ months of interplanetary space travel , while its flight systems have been designed to get it into the air on  a planet where the atmosphere is only about ​1100 as dense as Earth’s.

To put that in perspective: Ingenuity will be attempting to lift off in an atmospheric density that matches our own at 30,000 metres  – that’s almost four times the height of Mount Everest and a height well beyond the capabilities of any Earthbound helicopter. And where the lower gravity of Mars means Ingenuity ways just one third as much as it does when measured on Earth, this offers little in the way of compensation for the rarefied atmosphere.

Hence why Ingenuity is a proof-of-concept vehicle: just getting aloft with be a tremendous achievement – but if it can be shown to do so repeatedly, and to manoeuvre successfully, it could dramatically alter future robotic and human missions to Mars by providing  aerial support for them as terrain scouts or standalone science vehicles carrying their own payloads  operating remotely or – in the case of human missions – flown drone-like from a base of operations.

The first phase of operations for the mission was for Perseverance to scout the land close to its landing point – Octavia E. Butler Landing – to  find a suitable area of level ground over which Ingenuity can fly. This required finding an area some 90 metres in length and roughly 12-15 metres wide relatively clear of significant obstacles that might limit landing options., and with an area 10 metres on a side from which the first flight will be made and which has been dubbed “the airfield”. 

The flight zone and “the airfield”, the area in which Ingenuity will be test flown. Credit NASA

This deployment requires a number of actions to occur, the first of which came on Sunday, March 21st, when the cover that had been protecting Ingenuity was dropped from under the rover (see my previous Space Sunday update). Once Perseverance is correctly positioned at the centre of “the airfield”, the rest of the deployment will take place over a period of 6 Martian sols (days):

  • Sol 1: restraining bolts locking Ingenuity in place under the rover will be released.
  • Sols 2 and 3: a cable also holding the helicopter will be explosively released, triggering a motor that will gently rotate the helicopter down into an upright position beneath the rover, allowing two of Ingenuity’s landing legs to spring into their deployed position in the process.
  • Sol 4: the remaining two legs on Ingenuity will be released to snap into place. At this point, the helicopter will be slung under the rover, held in place by a single bolt and a set of power connectors.
  • Sol 5: Perseverance will carry out a full charge cycle of Ingenuity’s batteries – until now, the rover has only charged the batteries to around one-third their capacity, enough to keep the helicopter’s system warm.
  • Sol 6: The rover will be commanded to release the helicopter, allowing it to drop the 13 centimetres to the ground.

At this point, things will get a little risky: there will be no means to communicate with the helicopter, and its batteries can only supply it with power for 25 hours without recharge. In this time, a final visual check on Ingenuity must be carried out using the WATSON imager on  the rover’s robot arm, and then the rover must carefully reverse away from the helicopter to a distance of 5 metres.

Once at this distance, the rover will be able to act as a communications relay between mission control and the helicopter, allowing mission control to command the helicopter to switch to charging its batteries from its solar cells and upload the required flight software.

In all, the flight team have 30 days from the moment Ingenuity is released from Perseverance to complete the planned five flights. After this time, the rover must commence its own science programme. The flight team will therefore be looking to complete those five flights in as short a space of time as possible. For the first flight, Ingenuity will do little more than attempt to rise to a height of 3 metres, hover for 30 seconds and then land safely. After this, the remaining four flights will be for longer and to heights of around 5 metres, and for increasing distances down “the airfield”.

If we get past those [flights], we will assess:  did we meet all our objectives during those flights? Do we want to go back and retry some of those things? Or, if everything goes really well, then we might try to stretch our capabilities beyond those basic capabilities.    

– Ingenuity chief pilot Håvard Grip

The late Jakob van Zyl after whom the elevated position from which Perseverance will observe Ingenuity’s flights has been named. Credit: NASA

All of the flights will hopefully be documented by Perseverance its powerful Mastcam-Z camera system and two on-board microphones from an observation point some 60 metres from “the airfield”, which it will drive to prior to the first flight.

This observation point has been dubbed the Van Zyl Overlook in honour of key Ingenuity team member Jakob van Zyl, the former director for solar system exploration and associate director for project formulation and strategy at NASA’s Jet Propulsion Laboratory, who passed away unexpectedly in August 2020.

When it makes its flights, Ingenuity will both make history and carry a piece of history with it: attached to the Helicopter is a small piece of fabric taken from the Wright Brother’s 1903 biplane, credited with making the he first powered, controlled flight on Earth on December 17th, 1903.

‘Oumuamua is Likely a Piece of a Planet

In 2017 the Pan-STARRS astronomical observatory in Hawaii identified an object of extra-solar origin on a course that would carry it around the Sun. Named  ‘Oumuamua, meaning “scout” or “messenger” in Hawaiian, it was the first such object to be positively identified as coming from beyond the solar system,  although it is now believed that as many as five such object could pass through the solar system every year.

‘Oumuamua, however, was not only the first to be positively identified, it was also highly unusual – so much so that it couldn’t be classified as either an asteroid or a comet, as it exhibited behaviour common to both – and behaviour and attributes not found in either. This has lead to a variety of possible theories being put forward for it might be – up to and including the idea it was actually an interstellar probe created by an alien intelligence.

An artist’s impression of 1I/2017 U1 (or `Oumuamua), which was first seen by the Pan-STARRS 1 telescope in Hawaii on October 19th, 2017, and subsequently studied by a number of telescopes around the world, including the VLT of the European Southern Observatory (ESO). Credit: ESO / M. Kornmesser

However, two astrophysicists from Arizona State University believe they now have solved the mystery of ‘Oumuamua.Taking the more comet-like behaviours of the object, Steven Desch and Alan Jackson started looking for combinations of ices and volatiles that, when affected by the heat of the Sun, who produce the kind of reactions seen with ‘Oumuamua.

Their research lead them to a combination of nitrogen-dominant ices that, under computer modelling, not only produced the kind of non-tail generating outgassing seen with ‘Oumuamua, they they closely match combinations of nitrogen, methane and other ices found on Pluto and Neptune’s moon Triton.

These findings, coupled with further computer modelling, tend to suggest ‘Oumuamua  is likely a part of a Pluto-like planet orbiting a star somewhere in our stellar neighbourhood (separate estimates of data gathered on the object suggest it is around a billion years old, so must has originated fairly close to us, given its observed velocity through the solar system). If correct, then Densch and Jackson may not only have solved the nature of ‘Oumuamua , they may have shown that a new class of exo-planets exists: so-called “exo-Plutos”.

Rocket Lab Go Large

Rocket Lab’s proposed Neutron Rocket. Credit: Rocket Lab

Rocket Lab, the New Zealand-American private launch company I’ve mentioned a few time in these pages is proving itself to be every bit as capable as SpaceX – and to have a CEO with a good sense of humour.

Founded by Kiwi engineer Peter Beck, the company initially specialised in the small launch market with a sub-orbital sounding rocket called Ātea, before developing their highly innovative – and highly capable Electron Rocket, a vehicle specifically geared towards the sub-500 KG payload market, and which utilises an all composite design and 3D printed engines.

First launched in 2017, Electron is rapidly becoming a popular smallsat delivery system, and is evolving into a semi-reusable launch vehicle, with the first successful recovery of its first stage occurring in 2019. Whilst this took the form of a splashdown for the rocket, Rocket Lab eventually plan to catch the first stage of each Electron in mid-air using helicopters, removing their exposure to sea water and speeding up their refurbishment and re-use.

Such is the smallsat market – which includes customers up to and including NASA – Beck swore that his company would never need to “go large” with a launch system, and if they ever did, he would eat his hat.

Well, at the start of March 2021, Rocket Lab announced they are entering the mid-range launch vehicle market with a semi-reusable rocket they are calling Neutron, with the capability to lift up to eight tonnes to low Earth orbit and potentially 2 tonnes to the Moon, or 1.5 tonnes to Mars or Venus. What’s more, Neutron is being designed so it can in the future carry crewed vehicles.

The first Neutron flight is targeted for 2024 – which is an aggressive time frame, but Rocket lab have repeatedly demonstrated they’ll do exactly what they say they’ll do. And in keeping with that approach in the video announcing the development of the Neutron rocket, Peter Beck humorously showed he’d keep his word regarding hats and meals as well.

SpaceX

The anticipated flight of SpaceX Starship prototype SN11 had a further delay in the week. On Monday March 22nd, the vehicle underwent a pre-launch static fire test of its three Raptor engines in readiness for the 10 km flight. However, a review of data following the test prompted SpaceX to decide to swap-out one of the motors, a task that wasn’t completed until Thursday, Marsh 25th.

A second static fire test , followed by a possible launch, was scheduled for Friday, March 26th, However, a combination of weather and issues with the flight termination packages (used to destroy the vehicle in flight should it suffer a malfunction / veer dramatically off-course to pose a risk to life), lead to both the static fire and launch being scrubbed to allow further vehicle and  system check-outs. It’s now anticipated that the engine test will take place on Monday, March 29th, and could be followed by the test fight launch later in the day.

A unique view of Starship SN11 as engineers fit the flight termination packages ahead of the hoped-for launch at the start of the week, captured by RGV Aerial Photography

Thursday, March 25th also saw SpaceX make the news, this time as a result of the second stage of one of its Falcon 9 rockets lighting up the Pacific North-West of the United States and Canada.

The stage had been used in a March 4th launch of 60 Starlink broadband satellites for the company. to orbit. While the payload was successfully delivered, the second stage of the rocket failed to make a de-orbit burn that would have seen it make a controlled re-entry into the upper atmosphere and burn-up over open ocean.

Instead, the stage continued in order until March 25th, when it an uncontrolled re-entry that set it tumbling into a bright break-up that was seen by many on the ground both in American and Canada, prompting some scares that people were witnessing an airliner breaking up, with calls to local law enforcement agencies and also television news channels. As it was, no lives were at risk and none of the debris survived to impact the ground.