walking in space

'I didn't want to be known as the person who broke something on the Hubble telescope'

A former Nasa astronaut talks to us about his time in space, and the goal of humans reaching Mars.

531px-STS-61_Hubble_servicing Hoffman repairing the Hubble Nasa Nasa

DR JEFFREY HOFFMAN has clocked up more than 1,200 hours and 21.5 million miles in space.

Selected by Nasa in January 1978, Hoffman made five flights as a space shuttle astronaut, including the first mission to repair the Hubble Space Telescope in 1993. He’s currently a professor of aeronautics and astronautics at the Massachusetts Institute of Technology (MIT).

Hoffman will soon be in Ireland to teach at the International Space University’s 30th Space Studies Program (SSP17), which is happening at Cork Institute of Technology from 26 June to 25 August.

He recently spoke to about his time in space and thoughts on humans eventually reaching Mars.

On his fourth spaceflight, Hoffman (72) was one of four astronauts who helped repair the Hubble telescope.

After Hubble’s deployment in 1990, scientists realised the telescope’s primary mirror had a flaw called spherical aberration. The outer edge of the mirror was ground too flat by a depth of 2.2 microns (roughly equal to one-fiftieth the thickness of a human hair), Nasa explains.

wfpc_in_enclosure Nasa Nasa

This resulted in images that were fuzzy because some of the light from the objects being studied was being scattered. As part of the maintenance mission, new instruments were installed to correct this flaw.

Hoffman tells us it’s difficult for people who weren’t alive at the time to comprehend how vital this mission was.

“The mission was absolutely critical, it’s hard for people who weren’t alive at the time to comprehend that, like my students – they weren’t born when the Hubble was put into space.

It was an incredible disaster for Nasa and the astronomy community.

Given the critical nature of the mission, only people who had already done spacewalks could be involved.

“I had [done spacewalks] and I guess I had done a good job so I was chosen,” Hoffman recalls, adding that getting to put his hands on the telescope was “the thrill of a lifetime”.

When asked if he was nervous beforehand, he says: “I guess you have to have the right type of mentality [to be an astronaut]. I don’t tend to get nervous about things.”

International Space University / YouTube

He does, however, admit he and his colleagues were “scared we were going to mess up”.

I didn’t want to be known as the person who broke something on the Hubble that wasn’t already broken.

Hoffman notes that astronauts have “limited ability to move”, given the heavy spacesuits and big backpacks.

“We had to get right inside the telescope. You don’t want to bump into anything, there are a lot of very delicate optics.”

Luckily, it all went to plan.

The red planet

Much of the recent commentary about space is centred on humans reaching Mars.

Back in March, US President Donald Trump signed legislation that said manned missions to deep space, including to the red planet, would be Nasa’s main goal in the decades to come.

According to the text of the legislation — adopted by a rare unanimous vote in the Senate and House of Representatives — Nasa will work towards the goal of “a crewed mission to Mars in the 2030s”.

Nasa “shall continue the development of the fully integrated Space Launch System, including an upper stage needed to go beyond low-Earth orbit, in order to safely enable human space exploration of the Moon, Mars, and beyond over the course of the next century”, the text states.

Getting to Mars is also the goal of Mars One and Elon Musk’s SpaceX.

Sending people to live on the red planet, which lies about 140 million miles (225 million kilometers) away from Earth, will take a huge amount of money and technological advances.

Hoffman describes getting humans to Mars as the “end goal”, telling us “we can’t really imagine getting much further” with current technology.

He’s definitely not a fan of Mars One (the consortium has hit a number of snags), calling it “bogus”.

They don’t have a prayer … I don’t take them seriously, but I take SpaceX very seriously.

Hoffman says Musk’s plan to land a capsule on the surface of Mars by 2020 would be “a great step forward if it happens”, noting Nasa’s interest in the project.

He says one tonne is the current maximum weight that can land on Mars, while Musk wants to land a seven-tonne capsule on the planet’s surface.

“They might be able to get there. If they do, more power to them.”

Hoffman says companies such as SpaceX and Blue Origin are “willing and able to take more risks than Nasa is allowed to as it’s a government organisation”.

He wants to see more public-private cooperation in terms of space exploration, saying this could help progress deep space exploration.


Hoffman’s currently working on Moxie – an experiment that will go to Mars on the 2020 Rover. The goal is to produce oxygen on the planet for the first time, using local resources.

The red planet has a very thin atmosphere – about 1% of the density of Earth’s atmosphere – it’s about 95% carbon dioxide.

The plan is to use electricity to split the carbon dioxide molecules and get the oxygen out.

If successful, this would be a significant development. Hoffman says bringing oxygen from Earth to Mars is “very expensive” so Nasa is exploring alternative ways to produce oxygen there.

It we make oxygen up there, we’d basically be living off the land – as explorers have done since time immemorial.

“Everyone understands how oxygen works – we need it to breathe. What people don’t realise is the majority of oxygen required for the Mars mission is for the rocket.”

Hoffman says tens of tonnes of oxygen would be needed just to get a rocket to Mars, before any humans potentially on board needed it.

Lunar exploration

Getting humans to Mars is likely over a decade away and Hoffman believes more exploration on the Moon is needed in the meantime.

“It’ll be a long time before we actually get people on the surface of Mars, we need to get back to exploring on the surface of another planetary body.

“We’re lucky, the Moon is only a few days away. It’s not as easy as getting back from the (international) space station, but still a lot easier than Mars … If you’re on the way to Mars and there’s a problem you can’t turn back, you’re committed for a couple of years. It’s a much riskier proposition.”

hoffman Hoffman in his astronaut days Nasa Nasa

While the US has moved away from lunar exploration, other countries are still pursuing this and Hoffman would like to see international cooperation in this area.

He wants Nasa to start a lunar exploration initiative that would see the organisation work with other countries like it does on the International Space Station.

He thinks more lunar exploration could give insights that would help us get to Mars quicker.

No Apollo budget

Nasa currently has an annual budget of just over $19 billion (about €17 billion).

Hoffman says the budget isn’t comparable to what was being spent on space exploration during the Apollo era of the 1960s and 70s (taking into account inflation), when investment was spurred on by the Cold War.

He says “money was no object” then, but Nasa is “doing what it can with the budget it has” now.

‘Pale blue dot’

Many people will be familiar with the Pale Blue Dot image taken in 1990 by the Voyager 1 space probe from about six billion kilometers away. It shows how tiny Earth is in the great vastness of the universe and inspired Carl Sagan’s famous speech.

Hoffman says seeing the Earth from space in real life, as astronauts do, is obviously more impactful than just looking at an image.

“You get the sense of the earth as a planet, out there in the vastness of space.”

442px-Pale_Blue_Dot Pale Blue Dot Wikipedia Wikipedia

He explains that, given the hostility of most of the universe, “earth’s ability to support life is somewhat more precious” to astronauts.

On a sunny day (on earth) you could be in your backyard and look up at the big blue sky and it seems like it goes on forever … Being in space makes you appreciate the finiteness of the planet.

Hoffman notes that our atmosphere is “a very, very thin tiny blue line”, explaining: “If you had model of the Earth the size of a football, the atmosphere would be like the equivalent of a human hair.”

Climate change

Hoffman says a lot of astronauts have more of an interest in ecology and protecting the Earth’s environment when they return from space.

“They have much more of a sense that the planet is really pretty special.”

So what does he think of Donald Trump withdrawing the US from the Paris Agreement on climate change?

“The majority of people in the US disagree with him – at state level, I live in Massachusetts, we’re going to continue with all of the things that we were going to do regardless.”

Hoffman says Trump’s decision was “short-sighted”, adding: “It’s embarrassing what is going on in Washington right now, but that’s another story … I don’t want to minimise what he’s doing, but he clearly does not have the support of the majority of people.”

The Martian

Space is often explored in film, but not every attempt is realistic. Some, however, were pretty on the money.

Hoffman says: “The Martian did a very good job, they worked with Nasa to make it as realistic as possible.”

20th Century Fox / YouTube

He’s a fan of Apollo 13 too – which also worked with Nasa. He describes the movie as “very, very realistic”, saying: “They did an incredibly good job.”

One film which was a bit wide of the mark was Gravity. In Hoffman’s words, it was “visually quite stunning but nothing to do with what actually happens in space”.

At the end of the day, he believes any film that gets people “interested in and more excited about space” is a good thing.

More information on the International Space University progamme happening in Cork this summer can be read here. Note: Dr Buzz Aldrin, the second man to walk on the Moon, was expected to attend the launch on 27 June, but had to cancel due to medical advice.  

Contains reporting from © AFP 2017

Read: Nasa scientists to spend eight months in Hawaiian dome for ‘Mars simulation’

Read: In major announcement, Nasa confirms seven Earth-like planets have been discovered

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