Perhaps your flatmate has polished off the last beer in the fridge, diverging tastes in Netflix series have led to simmering tensions, or parental negotiations over home-schooling have descended into hostility.

Life in lockdown can fuel family tensions, sour friendships and drive a wedge between new romantic partners who have opted to self-isolate together. Help is on hand, however.

A former Nasa astronaut, Jay Buckey, has launched an online self-help toolkit aimed at replicating the kind of training designed to help astronauts cope with confinement in small spaces for extended periods.

“It’s challenging to be isolated with a small group of people and to not be able to get away,” said Buckey, who flew on a 16-day Space Shuttle Columbia mission that orbited the Earth 256 times. “Outer space and your own living room might be drastically different physically, but emotionally the stressors can be the same.”

The online training, called the Dartmouth Path Program, was developed to determine how the space programme can manage pressures brought on by long-duration spaceflight. It is already being tested in extreme environments such as research stations in Antarctica, but since social distancing restrictions came into force it has been made freely available to the public online.

It includes training on conflict resolution, mood management and self-assessment tools to be able to monitor signs of anxiety and stress.

For stress, the programme prompts the participant to consider whether they could be over-reacting, catastrophising or making judgments that don’t fit the evidence. Focused breathing and muscle relaxation techniques are outlined for when you are feeling anxious or angry.

The training also covers depression, which can set in when you feel restricted and unable to do the things that normally boost your mood, according to Buckey, who is now a professor of medicine at Dartmouth College.

The programme encourages people to select problems and find aspects they can improve or solve and to brainstorm positive steps they can take. It encourages people to think about a single enjoyable activity that is possible to do each day. “If you focus constantly on what you can’t do or things you want to do or that you’re isolated, that’s not good for mood,” said Buckey.

Keeping a balance between group time and private time is crucial, he said. “You need to allow people their privacy but not to allow them to become isolated and separated from a group,” he said. “If someone’s spending all their time in their room with their door closed, that’s not great. Forcing people to take part in group activities that they’re just not into – that’s not good either.”

According to Buckey, Nasa and other agencies now give psychological training to avoid conflict between crew members, but the problem blighted some missions in the past. The Russian cosmonaut Valentin Lebvedev, who documented his 211-day stay onboard the Space Station Salyut 7 with Anatoly Berezovoy, wrote: “We don’t understand what’s going on with us. We silently walk by each other, feeling offended. We have to find some way to make things better.”

Scientists on Antarctic missions have also struggled with isolation, Buckey said, pointing to the notes of Jean Rivolier, a French psychologist and chief doctor on several Antarctic expeditions, describing the dismal morale of one party in the 1990s.

“One subject returned early to Sydney on psychological grounds, because he was homesick for his family and he became progressively more depressed,” Rivolier wrote. “When the others returned they were humourless, tired, despondent and resentful. None had found the Antarctic experience to be enjoyable, not so much from any rigours of the climate, terrain or personal hardships as from inconsiderate and selfish behaviour.”

Pete Davis, an oceanographer at the British Antarctic Survey, said the uncertain length of missions to the south pole, due to weather considerations, was challenging. The “worst thing to do”, he said, was to focus on when isolation would end. “The best thing to avoid is what’s going to happen in three months time when you’ve only just started,” he said. “All you can control is what’s going to happen today or tomorrow.”

Davis, who returned from a three-month Antarctic mission in February only to be plunged back into confinement at home, advised that simple, considerate gestures could help ensure harmony.

“In Antarctica, full-blown conflict doesn’t tend to happen, but the small niggle of ‘that’s so annoying’ does,” he said. “Just things like if you’re going to make a cup of tea, make sure you ask everyone as well. It’s such a minor thing but it can get under people’s skin.”